blob: 267565894db929013c88d75be65093f693546b8b (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
* ARM PrimeCell PL330 DMA Controller
The ARM PrimeCell PL330 DMA controller can move blocks of memory contents
between memory and peripherals or memory to memory.
Required properties:
- compatible: should include both "arm,pl330" and "arm,primecell".
- reg: physical base address of the controller and length of memory mapped
region.
- interrupts: interrupt number to the cpu.
Optional properties:
- dma-coherent : Present if dma operations are coherent
- #dma-cells: must be <1>. used to represent the number of integer
cells in the dmas property of client device.
- dma-channels: contains the total number of DMA channels supported by the DMAC
- dma-requests: contains the total number of DMA requests supported by the DMAC
Example:
pdma0: pdma@12680000 {
compatible = "arm,pl330", "arm,primecell";
reg = <0x12680000 0x1000>;
interrupts = <99>;
#dma-cells = <1>;
#dma-channels = <8>;
#dma-requests = <32>;
};
Client drivers (device nodes requiring dma transfers from dev-to-mem or
mem-to-dev) should specify the DMA channel numbers and dma channel names
as shown below.
[property name] = <[phandle of the dma controller] [dma request id]>;
[property name] = <[dma channel name]>
where 'dma request id' is the dma request number which is connected
to the client controller. The 'property name' 'dmas' and 'dma-names'
as required by the generic dma device tree binding helpers. The dma
names correspond 1:1 with the dma request ids in the dmas property.
Example: dmas = <&pdma0 12
&pdma1 11>;
dma-names = "tx", "rx";
|
